Schedule IV - Mortgage Loans on Real Estate (Parenthetical) (Detail) (USD $)	12 Months Ended
Dec. 31, 2013
Mortgage Loans on Real Estate [Line Items]
Carrying Amount of Loans	$ 2,087,888,000
Fully impaired subordinate loans	108,800,000
Principal balance	10,500,000
Subordinate loans number of delinquent days	Greater than 90 days delinquent
Senior Mortgages Loans [Member]
Mortgage Loans on Real Estate [Line Items]
Contiguous subordinated loans	$ 68,600,000
Minimum [Member]
Mortgage Loans on Real Estate [Line Items]
LIBOR floor rate	0.20%
Maximum [Member]
Mortgage Loans on Real Estate [Line Items]
LIBOR floor rate	1.00%

The carrying amount of the outstanding balance due under the mortgage loan.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 10

-Section S99

-Paragraph 6

-Subparagraph (SX 210.5-04.(c) Schedule IV)

-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 29

-Article 12

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule IV

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 310

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-29)

-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant